In my U.S. Pat. No. 4,389,198 of June 29, 1983, there is shown and described an outboard motor system comprising a support adapted to be bolted to the deck of a vessel for supporting a prime mover with its drive shaft in a horizontal position transversely of the vessel and for supporting an outboard propulsion assembly outboard of the vessel with its input shaft parallel to the output shaft of the prime mover for pivotal movement in a vertical plane at right angles about an axis coinciding with the axis of the input shaft. The system shown therein embodies the advantages that; no struts or other supporting structure below deck are required to hold the propulsion assembly in its operative position, hence, it may be easily installed for use or removed without having to break weldments or detach bolts below deck; it is free to pivot about its pivot axis in the event that, if it strikes an underwater obstruction, it avoids damage to the propeller or its supporting structure; it can be elevated to an out-of-water position above deck for repair when necessary; the input shaft can be interchangeably mounted to either side, that is, to the right or left side depending on the mounting of the prime mover; and that, because of the parallel relationship of the drive and input shafts, the drive for the propulsion assembly can be maintained regardless of its pivoted disposition which enables maintaining control of the vessel at all times. In the aforesaid system, control is provided aboard the vessel through mechanical linkage. It is the purpose of this invention to provide the aforesaid system with certain added improvements without forfeiting the advantages embodied therein by providing an integrated hydraulic control system in lieu of the mechanical control system wherein there is a hydraulic clutch for establishing the drive from the input shaft to the propeller, thus to avoid the need for an onboard clutch system, wherein there is a hydraulic motor for steering, thus avoiding the need for a steering system on board the vessel, wherein there is a hydraulic cylinder for maintaining the propulsion assembly in its operative position with its propeller submerged while permitting it to be displaced in the event of impact with an underwater structure and to restore it to its operative position after it has passed over an obstruction to thereby maintain control without damage to the propulsion assembly and to enable elevating the propulsion assembly when desired, wherein there is a hydraulic pump coupled directly to the input shaft so that hydraulic pressure is available for the hydraulic clutch, the hydraulic motor and the hydraulic cylinder whenever the input shaft is being driven by the prime mover for effecting operation of the aforesaid functions independently of each other.